American Go E-Journal

AlphaGo completed its sweep of world number one professional Ke Jie 9P on Saturday, winning the third and final game of their match by resignation. Ke called it “one of the greatest matches that I’ve had.” The game once again showcased exciting and surprising moves from both sides, the first arising almost immediately on move 7, a four-space extension from the upper right in which AlphaGo played one space closer to the corner than in the usual Chinese opening. White 20 was a counter-intuitive second-line probe into Black’s framework on the lower right, showcasing Ke Jie’s superb positional judgment.

When Ke Jie attained a local advantage in the centre, AlphaGo switched to build a powerful framework on the top that spurred White to invade. The action came to a head when Ke Jie sacrificed the territory on the upper side to AlphaGo, gaining initiative to pressure the lower left. After AlphaGo protected its group, the match proceeded towards the endgame. Ke Jie revived his stones in the upper left to take the territorial lead, but this sequence left AlphaGo just enough latitude to take control of his group in the centre, and White resigned after 209 moves.

“We held this event aiming to discover new insights into this ancient, beautiful game,” said DeepMind CEO Demis Hassabis. “I can safely say that what has taken place since Tuesday has exceeded our highest hopes. We have seen many new and exciting moves, and we also saw AlphaGo truly pushed to its limits by the great genius Ke Jie.”